Underwater full coverage path planning in unknown waters based on random search two-stage planning model algorithm

［Objective］Aiming at typical application scenarios in which underwater vehicles perform search tasks such as preemptive submarine harassment and patrol hunting in a target sea area, this paper explores methods for achieving efficient and seamless coverage search in unknown waters under the conditions of no prior information and being constrained by detection capabilities.［Method］By establishing a mathematical model for search path planning in unknown waters and designing a heuristic solution method based on twostage planning for the random search strategy, the efficiency results of various search strategies in different shaped waters are obtained.［Results］In rectangular waters, parallel search or spiral search has the highest efficiency, and zigzag search strategy has the lowest efficiency; in circular waters, spiral search has the highest efficiency; in irregular waters, parallel search, zigzag search and spiral search cannot be directly applied, and random search can find near-optimal solutions without approximating the waters.［Conclusions］ The established mathematical model satisfies conditions such as "full coverage of unknown waters" and "completing the search in the shortest time". The designed random search two-stage planning model algorithm can plan a random search route that meets the full coverage requirements for any irregularly connected waters without discretizing the physical space of the battlefield, constraints, and decision variables.